The overall objectives of this project are to determine the manner in which excessive amounts of fluoride exert their toxicity and to determine the interaction of fluorides with other trace elements. The specific areas to be pursued during the coming year are a determination of the influence of F on Cu and Fe metabolism, an explanation of the manner in which elevated fluoride causes epinephrine release, and a determination of the basis for the drop in pyridine nucleotide levels observed when cultured cells are exposed to fluoride.